Image display apparatus

ABSTRACT

An image display apparatus for displaying an image corresponding to an image signal selectively inputs a first image signal and a second image signal having an aspect ratio different from that of the first image signal. When the second image signal is input, the second image signal is converted into an image signal corresponding to the aspect ratio of the first image signal, and the converted image signal is supplied to an image display unit for displaying an image corresponding to the aspect ratio of the first image signal. Thus, it is possible to display an image in a manner easy to observe, and to effectively utilize the display picture surface.

This application is a continuation of application Ser. No. 08/221,971,filed Apr. 4, 1994, now pending, which is a continuation of applicationSer. No. 07/672,125, filed Mar. 19, 1991, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an image display apparatus for displaying animage.

2. Description of the Prior Art

Heretofore, when displaying, for example, an image having an NTSCtelevision signal using a television monitor apparatus conforming to ahigh-definition television system, the signal is supplied to thetelevision monitor apparatus while increasing the number of scanninglines for the NTSC (National Television Systems Committee) televisionsignal so as to conform to the high-definition television system. Highdefinition television is generally recognized as a system which uses anincreased number of horizontal lines of resolution per frame to enhancepicture quality. Thus, as shown in FIG. 1, an image (reference numeral21) of the NTSC television signal is displayed on a predeterminedposition on the picture surface (reference numeral 22) of the televisionmonitor apparatus.

In the above-described conventional method, however, a blank portion onwhich an image is not displayed is present on the picture surface of thetelevision monitor apparatus, as shown in FIG. 1, due to a difference inaspect ratio between the NTSC system and the high-definition televisionsystem. Such a blank portion is very uncomfortable to observe. Inaddition, the display picture surface of the television monitorapparratus cannot be effectively utilized.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an image displayapparatus which can solve the above-described problems.

It is another object of the present invention to provide an imagedisplay apparatus which can display an image in a manner easy toobserve.

These objects are accomplished, according to one aspect of the presentinvention, by an image display apparatus for displaying an imagecorresponding to an image signal, comprising an image display unit fordisplaying an image corresponding to an aspect ratio of a first imagesignal, and an image signal supply means for selectively inputting thefirst image signal and a second image signal having an aspect ratiodifferent from that of the first image signal, for converting the secondimage signal into the image signal corresponding to the aspect ratio ofthe first image signal when the second image signal has been input, andfor supplying the image display unit with the converted signal.

It is still another object of the present invention to provide an imagedisplay apparatus which can effectively utilize its display picturesurface.

This object is accomplished, according to another aspect of the presentinvention, by an image display apparatus for displaying an imagecorresponding to an image signal, comprising an image display unit fordisplaying an image corresponding to an aspect ratio of a first imagesignal, image signal conversion means for inputting a second imagesignal having an aspect Patio different from that of the first imagesignal, and for converting the input second image signal into an imagesignal corresponding to the aspect ratio of the first image signal, anddisplay control means for controlling the display unit so as to displaythe image signal formed by the image signal conversion means on a firstdisplay picture surface of the image display unit, and to display animage corresponding to another information on a second display picturesurface which is present on the same picture surface as the firstdisplay picture surface and is different from the first display picturesurface.

The foregoing and other objects and features of the present inventionwill become more apparent from the following detailed description of thepreferred embodiments taken in connection with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a display picture surface of a conventional imagedisplay apparatus;

FIG. 2 is a block diagram showing the schematic configuration of animage display apparatus according to a first embodiment of the presentinvention;

FIG. 3 illustrates a display picture surface of the image displayapparatus shown in FIG. 2;

FIG. 4 is a block diagram showing the schematic configuration of animage display apparatus according to a second embodiment of the presentinvention;

FIG. 5 is a block diagram showing the schematic configuration of animage display apparatus according to a third embodiment of the presentinvention;

FIG. 6 illustrates a display picture surface of the image displayapparatus shown in FIG. 5; and

FIG. 7 is a block diagram showing the schematic configuration of animage display apparatus according to a fourh embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be explained with reference to preferredembodiments of the invention.

FIG. 2 is a block diagram showing the schematic configuration of animage display apparatus according to a first embodiment of the presentinvention.

In FIG. 2, a high-definition television signal and an NTSC televisionsignal are input to input terminals 1 and 5, respectively.

By operating an operation unit 3, the operator connects a switch 2 toside H (high definition signal) when displaying an image of thehigh-definition television signal on a monitor unit 4, and connects theswitch 2 to side N (NTSC signal) when displaying an image of the NTSCtelevision signal.

When displaying the image of the high-definition television signal, thehigh-definition television signal is directly supplied to the monitorunit 4 via the switch 2, and the high-definition television image isdisplayed on the monitor unit 4.

The display operation of an NTSC television image in the presentembodiment will now be explained.

Each of the elements shown in block outline in FIG. 2, as well as inFIGS. 4, 5 and 7, is well known per se and its specific type prconstruction is not critical to carrying out the invention or fordisclosure of the best mode for carrying out the invention.

In FIG. 2, by operating the operation unit 3, the operator connects theswitch 2 to side N when displaying the NTSC television image on themonitor unit 4.

The NTSC television signal input to the input terminal 5 is convertedinto a digital signal by an A/D converter 6, and the converted signal issupplied to a video signal converter 7.

In order to conform the horizontal scanning period of the digitized NTSCtelevision signal output from the A/D converter 6 to a high-definitiontelevision signal, the video signal converter 7 performs expansionprocessing by interpolation, and supplies a video memory 9 with theresultant signal.

A synchronizing signal corresponding to the high-definition televisionsignal is supplied from a memory control circuit 8 to the video signalconverter 7, which performs the above-described expansion processing inaccordance with the synchronizing signal output from the memory controlcircuit 8.

The television signal subjected to the above-described expansionprocessing for the horizontal scanning period by the video signalconverter 7 is first stored in the video memory 9, which performsinterpolation processing in order to expand the television signal in thevertical direction in accordance with the expansion processing for thehorizontal scanning period of the television signal performed by thevideo signal converter 7.

If the television signal subjected to the above-described expansionprocessing in the vertical direction by the video memory 9 is displayedon the monitor unit 4 as it is, part of the picture frame in thevertical direction corresponding to the television signal cannot bedisplayed due to the aspect ratio of the high-definition televisionsignal.

In order to solve such a problem, by operating the operation unit 3, theoperator indicates the display position of the picture framecorresponding to the television signal on the monitor unit 4 to thememory control circuit 8, which assigns a read address corresponding tothe display position indicated by the operation unit 3 to the videomemory 9. Image data stored in the assigned address in the video memory9 are read, and are supplied to a D/A converter 10.

The D/A converter 10 converts the image data supplied from the videomemory 9 into analog data, and supplies the converted data to themonitor unit 4 via the switch 2 connected to side N. Thus, an imagesubjected to expansion processing is displayed on the display picturesurface of the monitor unit 4, as shown in FIG. 3.

As shown in FIG. 3, by performing the above-described processing, ablank portion which has previously been present when displaying an imagecorresponding to an NTSC television signal on a monitor apparatusconforming to a high-definition television signal is not present, and itbecomes therefore possible to effectively utilize the display picturesurface of the television monitor apparatus.

A second embodiment of the present invention will now be explained withreference to FIG. 4.

In FIG. 4, like components as those in the FIG. 2 embodiment areindicated by like numerals, and a detailed explanation thereof will beomitted.

In FIG. 4, by operating an operation unit 11, the operator connects theswitch 2 to side N when displaying an NTSC television image on themonitor unit 4.

An NTSC television signal input to the input terminal 5 is convertedinto a digital signal by the A/D converter 6, and the converted signalis supplied to the video signal converter 7 and a motion detectingcircuit 12.

In order to conform the horizontal scanning period of the digitized NTSCtelevision signal output from the A/D converter 6 to a high-definitiontelevision signal, the video signal converter 7 performs expansionprocessing by interpolation, and supplies the video memory 9 with theresultant signal.

A synchronizing signal corresponding to the high-definition televisionsignal is supplied from a memory control circuit 13 to the video signalconverter 7, which performs the above-described expansion processing inaccordance with the synchronizing signal output from the memory controlcircuit 13.

The television signal subjected to the above-described expansionprocessing for the horizontal scanning period by the video signalconverter 7 is first stored in the video memory 9, which performsinterpolation processing in order to expand the television signal in thevertical direction in accordance with the expansion processing for thehorizontal scanning period of the television signal performed by thevideo signal converter 7.

In the FIG. 2 embodiment, by assigning the display position of thepicture frame corresponding to the television signal on the monitor unitto the memory control circuit using the operation unit, assigned imagedata are read from among image data stored in the video memory, and aredisplayed on the monitor unit. In the FIG. 4 embodiment, however, theread address of image data stored in the video memory 9 is controlled sothat an image portion having the largest motion on the picture frame isdisplayed near the center of the picture surface of the monitor unit 4.

That is, the digitized television signal output from the A/D converter 6is supplied to the motion detecting circuit 12, which compares thepicture frame represented by the supplied digital television signal withthe precedent picture frame, detects a portion having the largest motionon the supplied picture frame, and outputs a detection signal to thememory control circuit 13.

The memory control circuit 13 assigns a read address so that image dataassigned by the detection signal supplied from the motion detectingcircuit 12 are situated near the center of the display picture surfaceof the monitor unit 4, reads image data stored in the assigned addressin the video memory 9, and supplies the D/A converter 10 with the data.

The D/A converter 10 converts the image data supplied from the videomemory 9 into analog data, and supplies the monitor unit 4 with theconverted data via the switch 2 connected to side N. Thus, an image isdisplayed on the display picture surface of the monitor unit 4 whereinan image portion having the largest motion is situated near the centerof the picture surface.

As described above, in the FIG. 4 embodiment, it becomes possible todisplay an image so that an image portion having the largest motion issituated near the center of the display picture surface of the monitorapparatus in accordance with the motion of the image.

As explained above, according to the first and second embodiments, itbecomes possible to display an image in a manner easy to observe, and toeffectively utilize the display picture surface.

FIG. 5 is a block diagram showing the schematic configuration of animage display apparatus according to a third embodiment of the presentinvention. FIG. 6 shows a display example on the display unit of theimage display apparatus shown in FIG. 5.

In FIG. 5, a tuner unit 104 generates NTSC television signals. An A/Dconverter 105 converts an analog signal into a digital signal. An upconverter 106 converts the television signal digitized by the A/Dconverter 105 from an NTSC television signal into a television signal ofa high-definition system, A line memory 107 stores digital televisionsignals from the up converter 106, and the like. An information datagenerator 108 generates information data, such as time, the date and thelike. A character generator 109 generates display data corresponding tothe information data supplied from the information data generator 108and display data corresponding to information other than theabove-described time and date. An address controller 110 controls thewrite positions of digital television signals supplied from the upconverter 106 to the line memory 107, and the write positions of displaydata supplied from the character generator 109. An I/F (interface)circuit 111 converts assigned data from an operation unit 113 havingswitches, variable resistors, joy sticks and the like into control datafor controlling the address controller 110. A D/A converter 112 convertsa digital signal output from the line memory 107 into an analog signal,and outputs the converted signal to a display unit (not shown).

In the configuration shown in FIG. 5, an NTSC television signalgenerated from the tuner unit 104 is supplied to the A/D converter 105,and is converted from an analog television signal into a digitaltelevision signal by the A/D converter 105. The digital televisionsignal is converted into a high-definition television signal by the upconverter 106. The up converter 106 supplies the address controller 110with a horizontal synchronizing signal synchronized with the digitaltelevision signal for one line output from the up converter 106.

The information data, such as time, the date and the like, (theinformation data, such as the month, day, hour, minute, second and thelike) generated from the information data generator 108 are input to thecharacter generator 109. After the digital television signal for oneline has been supplied from the up converter 106 to the line memory 107in accordance with the horizonal synchronized signal supplied from theup converter 106, the character generator 109 generates a charactersignal representing time and the date corresponding to the digitaltelevision signal.

By operating the operation unit 113 having the switches, variableresistors, joy sticks and the like, assigning data for assigning thedisplay position of an image, the display position of information, andthe like on the display unit are converted into control data forcontrolling the address controller 110 by the I/F circuit 111, and theconverted data are input to the address controller 110. The addresscontroller 110 controls the write address of the digital televisionsignal supplied from the up converter 106 in the line memory 107 inaccordance with the control data from the I/F circuit 111. That is, inorder to store the digital television signal in the line memory 107making the address corresponding to the display position of the imageassigned by the assigning data supplied from the operation unit 113 aleading write address, and to store the character signal generated fromthe character generator 109 in addresses from the address next to thefinal write address for the digital television signal output from the upconverter 106 and stored in the line memory 107 until the final writeaddress of the line memory 107, the address controller 110 generatescontrol data for controlling the write address of the line memory 107when writing the digital television signal and the character signal inthe line memory 107. The line memory 107 sequentially writes respectivesignals in accordance with the control data generated from the addresscontroller 110.

After the storage operation of the line memory 107 has been completed asdescribed above, the stored signals are sequentially read from theleading address of the line memory 107, converted from digital signalsinto analog signals by the D/A converter 112, and output to anddisplayed on the display unit. Thus, on a display unit 201 of a highdefinition image display apparatus as shown in FIG. 6, it becomespossible to perform a display corresponding to other information (forexample, a clock or the like) on a blank portion 202 in addition to thedisplay (reference numeral 203) of the television image.

Although, in the present embodiment, a display corresponding to time isperformed as information other than the television image, an imagecorresponding to a television signal generated from a TV camera in asystem, such as a door interphone, a TV telephone or the like, may alsobe displayed as other information.

FIG. 7 is a block diagram showing the configuration of an image displayapparatus according to a fourth embodiment of the present invention. InFIG. 7, like components as those shown in the FIGS. 5 and 6 embodimentsare indicated by like numerals, and a detailed explanation thereof willbe omitted.

In FIG. 7, a frame memory 115 stores digital television signals suppliedfrom the up converter 106. An address controller 114 controls the writepositions of digital television signals supplied from the up converter106, the reading operation of image data stored in a frame memory 116(to be desribed later), and the writing operation of the read image datain the frame memory 115.

A video-signal separation circuit 117 separates a video-signal portionfrom a television signal generated from a TV camera in a system, such asa TV telephone, a door interphone or the like, input via input terminal120. A synchronizing-signal separation circuit 118 separates asynchronizing-signal portion from the television signal input via theinput terminal 120. The frame memory 116 digitizes the video signalseparated from the television signal by the video-signal separationcircuit 117 in synchronization with the synchronizing signal separatedby the synchronizing-signal separation circuit 118, and stores thedigitized signal.

In the configuration shown in FIG. 7, the NTSC television signalgenerated by the tuner unit 104 is supplied to the A/D converter 105,and is converted from an analog television signal into a digitaltelevision signal by the A/D converter 108. The digital televisionsignal is converted into a high-definition television signal by the upconverter 106. The up converter 106 supplies the address controller 114with a horizontal synchronizing signal synchronized with the digitaltelevision signal for one line output from the up converter 106.

The television signal generated from the TV camera in a system, such asa TV telephone, a door interphone or the like, is input to inputterminal 120. The video-signal separation circuit 117 separates avideo-signal portion from the television signal, and thesynchronizing-signal separation circuit 118 separates asynchronizing-signal portion from the television signal. The videosignal separated by the video-signal separation circuit 117 is digitizedin synchronization with the synchronizing signal separated by thesynchronizing-signal separation circuit 118, and the digitized signal isstored in the frame memory 116.

By operating the operation unit 113 having the switches and the like,assigning data for assigning the display position of an image on adisplay unit (not shown) and the display position of information, andthe like are converted into control data for controlling the addresscontroller 114 by an I/F circuit 119, and the converted data are inputto the address controller 114. The address controller 114 controls thewrite address of the digital television signal supplied from the upconverter 106 in the frame memory 115 in accordance with the controldata from the I/F circuit 119. That is, the digital television signal isstored in the frame memory 115 making the address corresponding to thedisplay position of the image assigned by the assiging data suppliedfrom the operation unit 113 a leading write address. Image data storedin the frame memory 116 are read in accordance with a command from theaddress controller 114, and are written in the frame memory 115 in aportion where the digital television signal supplied from the upconverter 106 is not stored. After the above-described storage operationof the frame memory 115 by the address controller 114 has beencompleted, the stored signals are sequentially read from the leadingaddress of the frame memory 115, are converted from digital signals intoanalog signals by the D/A converter 112, and the converted signals areoutput to and displayed on the display unit. Thus, it becomes possibleto perform a display corresponding to another image on a blank portionin addition to the display of the television image on the display unitof the high definition image display apparatus. It is also possible todisplay an image signal as an image wherein a shorter side of the imagesubstantially coincides with a shorter side of the display of thetelevision image on the display unit.

As explained above, according to the present embodiment, an imageobtained by up-converting a television signal of the NTSC system or thelike into a high-definition television signal is moved within thepicture surface of the display unit, and an image corresponding to atelevision signal generated from a TV camera in a system, such as a doorinterphone, a TV telephone or the like, other than the above-describedtelevision signal is displayed on a blank portion on the picture surfacewhich is produced due to a difference in the aspect ratio between theNTSC television system and the high definition television system. Hence,it is possible to effectively utilize the blank portion on the displayunit of the image display apparatus. Furthermore, by displaying an imagecorresponding to a television signal other than the television signalobtained by up-converting the NTSC television signal into thehigh-definition television signal on the blank portion, it is possibleto display another image without losing part of the image obtained bythe up-conversion.

What is claimed is:
 1. A television receiver for receiving either one ofa first television signal and a second television signal and displayingan image corresponding to the received first television signal or thesecond television signal, comprising:an image display unit fordisplaying an image having a display picture surface of an aspect ratiocorresponding to the aspect ratio of a first television image indicatedby the first television signal, said image corresponding to the firsttelevision signal or the second television signal; television signalreceiving means for selectively receiving the first television signaland the second television signal having an aspect ratio different fromthat of the first television signal; television signal forming means forforming a third television signal indicating a second television imagehaving a short side which coincides with the short side of a displaypicture surface on said image display unit on the basis of the secondtelevision signal received by said television signal receiving means;storage means for storing the third television signal and supplying thestored third television signal to said image display unit, said storagemeans having a first storage area for storing the third televisionsignal formed in said television signal forming means and a secondstorage area different from said first storage area; image signalgenerating means for generating an image signal indicating an imageother than that indicated by the third television signal; and controlmeans for controlling a signal writing and reading operation in saidstorage means so that after the second television signal is received insaid television signal receiving means, the third television signalformed in said television signal forming means is written in the firststorage area of said storage means, the image signal generated from saidimage signal generating means is written in said second storage area ofsaid storage means, and the signals written in the first and secondstorage areas of said storage means are read out to said image displayunit in synchronism with the first television signal.
 2. A televisionreceiver according to claim 1, wherein said image signal generatingmeans generates the image signal corresponding to an image indicatingthe date.
 3. A television receiver according to claim 1, wherein saidimage display unit displays the image corresponding to the image signalgenerated from said image signal generating means outside of the displaypicture surface displaying the second television image corresponding tothe third television signal.
 4. A television receiver according to claim1, further comprising display picture surface position assigning meansfor assigning a display position of the third television imagecorresponding to the third television signal formed in said televisionsignal forming means on the display picture surface of said imagedisplay unit, said storage operation control means being arranged sothat the third television signal formed by said television signalforming means should be stored in the first storage area of said storagemeans corresponding to the display position assigned by said displaypicture surface position assigning means.